ML19329D261

Regulatory Audit Summary Confirmation of a Plants Implementation of Nuclear Energy Institute 19-02, Guidance for Assessing Open Phase Condition Implementation Using Risk Insights

ML19329D261
Person / Time
Site:	Nine Mile Point
Issue date:	11/25/2019
From:	Alexander Schwab NRC/NRR/DRA/APOB
To:	Bryan Hanson Exelon Generation Co
References
Download: ML19329D261 (5)

Text

November 25, 2019 Mr. Bryan C. Hanson Senior Vice President, Exelon Generation Company, LLC President and Chief Nuclear Officer (CNO), Exelon Nuclear 4300 Winfield Road Warrenville, IL 60555

SUBJECT:

NINE MILE POINT NUCLEAR STATION UNIT 2 REGULATORY AUDIT

SUMMARY

RE: CONFIRMATION OF A PLANTS IMPLEMENTATION OF NUCLEAR ENERGY INSTITUTE 19-02, GUIDANCE FOR ASSESSING OPEN PHASE CONDITION IMPLEMENTATION USING RISK INSIGHTS

Dear Mr. Hansen:

This letter is being sent to document the results of an audit conducted by the U.S. Nuclear Regulatory Commission (NRC) at Nine Mile Point Nuclear Station, Unit 2. The NRC conducted the audit according to the audit plan, Regulatory Audit in Support of Confirmation of a Plants Implementation of Nuclear Energy Institute (NEI) 19-02, Guidance for Assessing Open Phase Condition Implementation Using Risk Insights, (Agencywide Documents Access and Management System Accession No. ML19281D386). Nine Mile Point (NMP) 2 has decided to use NEI 19-02 to risk-inform the decision of whether to implement the Open Phase Isolation System to provide alarm and indication to the control room operators as opposed to automatic actuation mode in response to an Open Phase Condition (OPC). One of the purposes of the audit was to identify key areas to address in a revision to the Temporary Inspection (TI) on OPC response to accommodate a plant that chose to use NEI 19-02 to stay in alarm only mode to address an OPC. This was done by investigating whether NMP 2 appropriately implemented the guidance in NEI 19-02. The audit also helped to determine whether the implementation of NEI 19-02 could be an appropriate alternate approach consistent with the revised Voluntary Industry Initiative on OPC response. The audit took place from October 21th-October 24th, 2019. The audit team was comprised of a Reliability and Risk Analyst and an Electrical Engineer from NRC Headquarters.

The audit began on October 21st, 2019, with an entrance meeting between the NRC and the licensee's staff and contractors. During the audit, the NRC participated in a technical review according to the audit plan. This technical review focused on how the methodology described in NEI 19-02 was implemented and the application (or temporary changes) of the plant specific PRA model of record within the context of applying the 19-02 methodology. It also included reviewing the training conducted and procedures required to address OPC to help verify the Human Reliability Analysis (HRA) documented in the licensees assessment, as well as reviewing the supporting documentation behind other key assumptions described in the licensees assessment and PRA model.

On October 23rd, 2019, at the conclusion of the audit, the NRC participated in an exit meeting with the licensee's staff. During the exit, the NRC discussed recommendations that it would be incorporating into the revision of the TI. These recommendations included:

inspectors reviewing the training, procedures, and operator actions, and ensuring the

B.Hanson HRA described in NEI 19-02 matches the inspectors observations. Most importantly, inspectors should investigate the human action execution time described in the HRA. It was also identified that the revised TI would instruct the inspectors to verify assumptions listed in NEI 19-02, e.g. that the pump motors subjected to an OPC will be protected by their protective devices (especially if analysis indicates that failure will place them over the NEI 19-02 risk threshold). The team also identified that the NMP 2 HRA analysis was confusing (e.g., certain aspects of the HRA could have used more explanation, and there were incorrect graphs in one section due to a software error) and that moving forward, the HRA analysis in NEI 19-02 evaluations should be more clear. The team concluded that the audit did not identify any issues that would preclude NEI 19-02 from being an appropriate alternate approach consistent with the revised OPC Voluntary Industry Initiative. contains a list of documents reviewed by the team during the audit.

If you have any questions, please contact me at 301-415-8539 or via e-mail at Alexander.Schwab@nrc.gov.

Sincerely,

/RA/

Alexander H. Schwab, Reliability and Risk Analst PRA Oversight Branch Division of Risk Assessment Office of Nuclear Reactor Regulation

Enclosures:

1. List of Participants

2. List of Documents Reviewed cc: Listserv

LIST OF PARTICIPANTS U.S. Nuclear Regulatory Commission (NRC}Audit Team Alexander Schwab NRC/Audit Lead Hari Kodali NRC/Observer Enclosure 1

LIST OF DOCUMENTS REVIEWED DURING THE AUDIT The following documents were reviewed by the U.S. Nuclear Regulatory Commission (NRC) audit team during the audit. The documents generally included procedures that implement the actions described in response to an Open Phase Condition with the alarm in manual, the training on these procedures, the plants NEI 19-02 analysis, and other documentation verifying the assumptions used in the NEI 19-02 analysis.

• NEI 19-02, Guidance for Assessing Open Phase Condition Implementation Using Risk Insights

• N2-MISC-015, Nine Mile Point Nuclear Station

• N2-ARP-852600, 2CEC*PNL852 Series 600 Alarm Response Procedures

• N-NM-OPS-2102-QS-04, Unit 2 Open Phase ARP Quick Set

• Analysis No. EC-205, Rev No. 000

• EC-154, Rev. 5 - Starting Voltage Verification or Class 1E MOVs

• EC-154, Rev. 5, Disposition No. 05A

• EC-154, Rev. 5, CCN No. ECP-09-000139 EC-154-05.000

• EC-154, Rev. 5, CCN No. 008521, Rev.0

• EC-166, Rev.0 - 4160 VAC Safety Related Breakers Coordination

• EC-166, Rev.0, Disposition No. 00B Enclosure 2

B. Hanson

SUBJECT:

NINE MILE POINT NUCLEAR STATION UNIT 2 REGULATORY AUDIT

SUMMARY

RE: CONFIRMATION OF A PLANTS IMPLEMENTATION OF NUCLEAR ENERGY INSTITUTE (NEI) 19-02, GUIDANCE FOR ASSESSING OPEN PHASE CONDITION IMPLEMENTATION USING RISK INSIGHTS DATED:

11/25/2019 DISTRIBUTION:

PUBLIC PM File Copy ASchwab, NRR AZoulis, NRR HKodali, NRR RidsNrrDraApob Resource RidsNrrDeEeob Resource ADAMS Accession No.: ML19329D261 *via email OFFICE NRR/DRA/APOB NRR/DRA/APOB*

NAME ASchwab AZoulis DATE 11/25/2019 11/21/2019